Today: Moving from the individual to the collective
Evolution of communities
Evolution of communities: Nothing exists in isolation
Show me one single, isolated tree in a Appalachian forest…
Biological implications of change
Philosophical implications of change
Global change pressures affect biological interactions
Cascading effects across many species
Every time community composition changes (by species gains, losses, or altered timing, strength, or type of interactions), shit happens
This is what we are doing on (and to) the planet
Individual species move, adjust, adapt, die and we care about that, but it’s the cascading effects that can unravel the biosphere as we know it
Cascading effects: co-extinction
Obvious examples like co-extinction where direct interaction partners influence each other
e.g., most vulnerable are obligate interaction partners (can be hosts/mutualists, predators/prey, plants/herbivores prey, hosts/parasites, etc.)
Cascading effects: keystone predator
- But species impact each other even if they don’t interact directly through biotic interaction chains
Cascading effects: introduced species
And this doesn’t need to be a top-down keystone predator; it can be a bottom-up effect
Global worming
- The last ice sheet killed off earthworms in the northern 1/3 of North American
- worms—with their limited powers of dispersal—weren’t able to recolonize on their own
Humans move worms, via dirty ship ballast, horticultural plants, mulch and fishing bait. European earthworms live on every continent except Antarctica.
- North American hardwood forests develop a thick blanket of slowly decomposing leaves deposited over the course of years that create homes for insects, amphibians, birds, and native flowers
- worms breakdown this layer to quickly for plants to capture nutrients and insects lost their homes
Cascading effects: complex chains
- Changes can have impacts many
trophic levels away
- trophic levels = feeding relationships
Cascading effects: complex webs
And these biotic interaction chains are actually embedded in complex biotic interaction webs
Cascading effects: the big picture
And these biotic interaction chains are actually embedded in biotic interaction webs plus complex abiotic interactions (Chap 10)
Evolution of communities
So we come back to… Nothing exists in isolation
Biological implications of change
Philosophical implications of change
True interconnectedness
Web of life is not some cheesy new-age idea
It’s also not just a scientific concept
It’s represented in cultures around the world
And it is quite simply: TRUTH
The implications are staggering
True interconnectedness: Nothing exists in isolation
Even in modern social media culture, can you separate YOU from everything else?
True interconnectedness
The problem is that we feel isolated
True interconnectedness: This is about YOU
It is not only about the physical planet Earth, it is about OUR bodies, minds, spirits, and relationships that are being trashed and polluted
We are being told that we are isolated, not good enough, not important to the big picture
But it’s not true
We have to start telling – and believing - a different story
To make progress we must bustdown some of the walls of separation!
True interconnectedness: Friday open discussion
What are the impediments to feeling connected?
In our societies?
In our classrooms?
In our psyches?
Others?
Choose a subject to write about or find an article to discuss
Submit an short paragraph of your conclusions to Brightspace for participation